Miniature atomic clocks based on coherent population trapping (CPT) states in thermal atoms are an important component in many field applications, particularly where satellite frequency standards are not accessible. Cold-atom CPT clocks promise improved accuracy and stability over existing commercial technologies. Here we demonstrate a cold-atom CPT clock based on 87Rb using a high-contrast double-Λ configuration. Doppler frequency shifts are explained using a simple model and canceled by interrogating the atoms with counterpropagating light beams. We realize a compact cold-atom CPT clock with a fractional frequency stability of 4×10-11τ -1/2, thus demonstrating the potential of these devices. We also show that the long-term stability is currently limited by the second-order Zeeman shift to 2×10-12 at 1000 s. ©2013 American Physical Society.
|Pages (from-to)||042120-1 - 042120-5|
|Journal||Physical Review A - Atomic, Molecular, and Optical Physics|
|Publication status||Published - 2013|